From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Garrett Subject: Re: ACPI S3 suspend and LCD backlight Date: Mon, 14 Nov 2005 13:17:28 +0000 Message-ID: <20051114131728.GA22957@srcf.ucam.org> References: <200511130639.jAD6d42Y011608@dragonslair.panasol.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <200511130639.jAD6d42Y011608-MVZ+8Rc8O2bWg2f883+pGFGJXeKZcw9A@public.gmane.org> Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: yauh-acpi-CDzBh2wLF5MAvxtiuMwx3w@public.gmane.org Cc: acpi-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-acpi@vger.kernel.org On Sat, Nov 12, 2005 at 10:39:04PM -0700, yauh-acpi-CDzBh2wLF5MAvxtiuMwx3w@public.gmane.org wrote: > It appears something in the ACPI suspend code turns on the > LCD backlight to print out the diagnostic messages. Is there any > way to prevent this? Alternatively, is there a place in the drive > I can add a sequence to turn off the display just before it goes > to sleep? No, the ACPI suspend code doesn't do this (as far as I can tell). If you suspend from X, the kernel will switch away from X and X will restore the console state - which probably includes switching the backlight back on. > The xset turns off the backlight but as soon as it gets to the echo 3 line, > the LCD comes on and displays the ACPI status messages. It then then > proceeds to blank the screen but does NOT turn off the backlight. > If there is no way to disable the messages, I was hoping there is a > place I can hook into to twiddle the bit needed to disable the backlight. > Loading the video support module gives me an empty /proc/acpi/video directory. Try grabbing vbetool and do something like FGCONSOLE=`fgconsole` chvt 12 vbetool dpms off echo -n 3 >/proc/acpi/sleep chvt $FGCONSOLE -- Matthew Garrett | mjg59-1xO5oi07KQx4cg9Nei1l7Q@public.gmane.org ------------------------------------------------------- SF.Net email is sponsored by: Tame your development challenges with Apache's Geronimo App Server. Download it for free - -and be entered to win a 42" plasma tv or your very own Sony(tm)PSP. Click here to play: http://sourceforge.net/geronimo.php